KR20200081229A - Apparatus for monitoring the state of valve body, and hydraulic pressure driving apparatus - Google Patents

Abstract

The present invention relates to a valve body condition monitoring apparatus and a fluid pressure driving apparatus to easily and accurately investigate the degree of wear of a valve body or a moving unit. The valve body condition monitoring apparatus comprises: an acquisition unit acquiring positional information of the valve body from a flow control valve which controls a discharge amount of a working fluid by performing feedback control so as to fix the valve body moving in a valve housing at a target position; and a status estimating unit. In order to return to the target position when the valve body deviates from the target position, the status estimating unit estimates a status of the valve body based on at least one of the number of times per unit time the valve body is moved and a distance the valve body is separated from the target position within a predetermined time.

Description

Valve body condition monitoring device and fluid pressure driving device {APPARATUS FOR MONITORING THE STATE OF VALVE BODY, AND HYDRAULIC PRESSURE DRIVING APPARATUS}

This application is based on the Japanese patent application (Japanese Patent Application No. 2018-246000, filing date: 12/27/2018) and enjoys the preferential benefit from this application. By referring to this application, all the content of this application is included.

The present invention relates to a valve body condition monitoring device and a fluid pressure drive device.

One of the failures of the flow control valve that controls the discharge amount of hydraulic oil is leakage of hydraulic oil due to wear of the spool (also called a valve body) of the flow control valve. Originally, when the spool is in the neutral position, the hydraulic oil is reliably sealed, and when the spool moves from the neutral position, the hydraulic oil must be discharged.

However, when foreign matter is mixed in the hydraulic oil in the flow control valve, the surface of the spool is cut off by the foreign matter, and even if the spool moves to the neutral position, there is a fear that the hydraulic fluid leaks from the gap caused by the wear of the spool.

Even if the spool moves to the neutral position, when hydraulic oil leaks, it is a factor that causes the drive unit driven by the flow control valve or the actuator controlled by the drive unit to malfunction. In addition, when the amount of leakage of the hydraulic oil is excessive, the supply of hydraulic oil is insufficient, and a sufficient hydraulic pressure cannot be obtained, and the efficiency of the drive unit and the actuator is lowered.

If the degree of wear of the spool can be investigated without disassembling the flow control valve, it is preferable because the maintenance cost can be reduced. Further, when the drive unit is driven by hydraulic oil discharged from the flow control valve, it is also preferable if the degree of wear of the spool of the flow control valve can be checked without stopping the operation of the drive unit.

Japanese Patent Publication No. 2016-50785

The problem to be solved by the present invention is to provide a valve body condition monitoring device and a fluid pressure driving device capable of simply and accurately examining the degree of wear of a valve body or a moving part.

In order to solve the above problems, in one aspect of the present invention, from the flow control valve for controlling the discharge amount of the working fluid by performing feedback control to fix the valve body moving in the valve housing to the target position, the valve body An acquisition unit that acquires location information,

When the valve body is displaced from the target position, the valve body is based on at least one of the number of times per unit time the valve body is moved to return to the target position and the distance the valve body is deviated from the target position within a predetermined time. And a state estimator for estimating the state of.

A life prediction unit may be provided which predicts the life of the valve body based on the state of the valve body estimated by the state estimation unit over a predetermined period.

In another aspect of the present invention, a flow rate control valve having a valve body that moves in a valve housing and controlling the discharge amount of the working fluid,

A position detecting unit for detecting the position of the valve body in the valve housing,

A feedback control unit that performs feedback control to match the position of the valve body detected by the position detection unit to a target position;

When the position of the valve body is shifted from the target position, at least one of the number of times per unit time the valve body has been moved to return to the target position and the distance between the position of the valve body and the target body within a predetermined time. There is provided a fluid pressure drive device having a state estimator for estimating the state of the valve body based on the above.

Predetermined in at least one of the case where the number of times per unit time the valve body is moved exceeds the first threshold and the distance between the valve body and the target position within a predetermined time exceeds the second threshold A warning unit for performing warning processing may be provided.

A life prediction unit may be provided which predicts the life of the valve body based on the state of the valve body estimated by the state estimation unit over a predetermined period.

The state estimating unit may estimate the state of the valve body when the valve body is stopped at a predetermined position.

The state estimating unit may estimate the state of the valve body when the valve body is moving.

According to the discharge amount of the working fluid from the flow control valve, there is provided a different flow control valve for moving a valve body different from the valve body of the flow control valve,

The state estimating unit, when the position of the valve body is shifted from the target position, the number of times per unit time the valve body is moved to return to the target position and the position of the valve body are separated from the target position within a predetermined time. The state of the valve body may be estimated based on at least one of the distances and the position of the other valve body of the other flow control valve.

According to the present invention, it is possible to examine the degree of wear of the valve body or the movable part with simplicity and accuracy.

1 is a diagram showing a schematic configuration of a valve body condition monitoring device and a flow control valve according to the first embodiment.
Figure 2 (a) is a diagram showing a path through which the hydraulic oil leaks when the spool is in the neutral position, (b) is an example of moving the spool to the left by changing the target position, (c) is changing the target position It is a figure showing an example in which the spool is moved to the right.
It is a figure which shows schematic structure of the valve body state monitoring apparatus and flow control valve by 2nd Embodiment.
4 is a diagram showing a schematic configuration of a fluid pressure drive device equipped with an actuator.
5 is a diagram showing a schematic configuration of a fluid pressure drive device according to a modification of FIG. 4.

Hereinafter, one embodiment of the present disclosure will be described with reference to the drawings. In addition, in the drawings attached to the present specification, for convenience of illustration and ease of understanding, the scale and aspect ratio are appropriately changed from those of the actual ones and exaggerated. In addition, terms such as "parallel", "orthogonal", "equal", values of length and angle, etc., which are used in this specification to specify the shape and geometric conditions, and their degree, are strictly defined. It is not limited to, and will be interpreted to include the extent to which the same function can be expected. Hereinafter, embodiments of the present invention will be described in detail.

(First embodiment)

FIG. 1 is a diagram showing a schematic configuration of a fluid pressure drive device 10 having a valve body condition monitoring device 1 according to a first embodiment. The fluid pressure drive device 10 is provided with a flow control valve 2. The flow control valve 2 is provided with a valve rod 2b having one or more spools (valve bodies) 2a and a valve body condition monitoring device 1. The valve rod 2b is controlled to move left and right as illustrated, for example, by a current flowing through an electromagnetic coil (not shown). In addition, the valve rod 2b does not necessarily need to be moved by electric control such as an electromagnetic coil, but may be moved by another control method (for example, hydraulic control). Thus, the spool 2a moves in the valve housing of the flow control valve 2. The flow control valve 2 performs feedback control to fix the spool (valve body) 2a moving in the valve housing to the target position, and controls the discharge amount of the working fluid.

The flow control valve 2 of FIG. 1 is provided with a plurality of ports through which hydraulic oil flows in and out, and the flow of hydraulic oil from each port is controlled according to the position of the spool 2a. For example, the flow control valve 2 includes a port P1 through which hydraulic oil from the actuator flows, a port P2 through which the hydraulic oil is supplied from the flow control valve 2 to the actuator, and a hydraulic oil from the flow control valve 2 to the tank. It has a port P3 to discharge it. In addition, the type and number of ports provided in the flow control valve 2 are arbitrary.

The fluid pressure drive device 10 of FIG. 1 includes a position detection unit 3, a feedback control unit 4, and a valve body condition monitoring device 1. Of these, the feedback control unit 4 and the valve body condition monitoring device 1 constitute a part of the controller.

The position detection unit 3 has a valve body that moves within the valve housing. More specifically, the position detection unit 3 is disposed on one end side of the valve rod 2b, and detects the position of the one end of the valve rod 2b, thereby detecting the position of the spool 2a. The position detection unit 3 can be configured using a gap sensor or the like. The position information of the spool 2a detected by the position detection unit 3 is transmitted to the feedback control unit 4.

The feedback control unit 4 performs feedback control so that the position of the spool 2a matches the target position. The target position of the spool 2a can be changed according to the operation of the flow control valve 2. 1 shows an example in which the target position of the spool 2a is a neutral position. In the neutral position, hydraulic oil from the flow control valve 2 is sealed. That is, in the neutral position, essentially, hydraulic oil is not supplied from the outside to the flow control valve 2, and hydraulic oil is not supplied from the flow control valve 2 to the outside.

The feedback control unit 4 controls the movement of the valve rod 2b so that the current position of the spool 2a detected by the position detection unit 3 matches the target position. For example, when the valve rod 2b is being moved using an electromagnetic coil, the feedback control unit 4 controls the magnitude and direction of the current flowing through the electromagnetic coil.

The feedback control unit 4 can adjust the target position according to the amount of hydraulic oil discharged from the flow control valve 2. For example, when the spool 2a is worn and the hydraulic oil leaks even when the spool 2a is in the neutral position, the target position may be changed to suppress leakage of the hydraulic fluid. In this case, the feedback control unit 4 finely moves the spool 2a with the change of the target position.

2(a) is a diagram showing a path through which the hydraulic oil leaks due to the wear of the spool 2a when the spool 2a is in the neutral position. 2(b) shows an example in which the spool 2a is moved to the left by changing the target position, and FIG. 2(c) shows an example in which the spool 2a is moved to the right by changing the target position. have. As described above, when the hydraulic oil leaks from the neutral position of the spool 2a, the feedback control unit 4 changes the target position and moves the spool 2a to the left or right accordingly to suppress leakage of the hydraulic oil. Control is performed.

The valve body condition monitoring device 1 includes an acquiring section 16 and a state estimating section 5. The acquisition unit 16 acquires the position information of the spool 2a from the flow control valve 2.

In the state estimating section 5, when the spool 2a is displaced from the target position, the number of times per unit time the spool 2a is moved to return to the target position and the spool 2a is deviated from the target position within a predetermined time. Based on at least one of the distances estimated, the state of the spool 2a is estimated.

When the number of times per unit time of the spool 2a is large, it indicates that the position of the spool 2a rarely matches the target position. As described above, when the spool 2a is worn, even when the spool 2a is in the neutral position, since the hydraulic oil leaks, the target position is changed to suppress leakage of the hydraulic oil, and accordingly, the spool ( Since the position of 2a) also moves, the number of times per unit time increases. Therefore, when the number of times per unit time of the spool 2a exceeds a predetermined threshold (first threshold), the state estimating unit 5 estimates that the spool 2a is worn.

Moreover, when the distance to which the spool 2a moves relative to the target position is large, it indicates that the spool 2a is largely separated from the target position. As described above, when the spool 2a is worn, even when the spool 2a is in the neutral position, the hydraulic oil leaks, but the larger the amount of hydraulic oil leaking, the larger the target position. Therefore, when the distance that the spool 2a moves relative to the target position exceeds a predetermined threshold (second threshold), the state estimating unit 5 estimates that the spool 2a is worn. .

The state estimator 5 estimates the state of the spool 2a at the present time. The feedback control unit 4 continuously performs feedback control so that the position of the spool 2a matches the target position while the flow control valve 2 is operating, and accordingly, the state estimation unit 5 Also, the state of the spool 2a is continuously estimated. The state estimated by the state estimating section 5 may be a state indicating whether the spool 2a is worn or a state indicating the degree of wear.

The state estimated by the state estimation unit 5 at each time point may be stored in the storage unit 6 indicated by a broken line in FIG. 1, for example. The storage unit 6 stores the time information estimated by the state estimation unit 5 and the estimated state as a set. Thereby, the states at a plurality of time points within the period during which the feedback control unit 4 is performing feedback control can be sequentially stored in the storage unit 6. It is preferable that the information stored by the storage unit 6 can be output to the outside as necessary.

In addition, the valve body condition monitoring device 1 in FIG. 1 may include a warning unit 7 indicated by a broken line. The warning unit 7, when the state estimation unit 5 determines that the number of times per unit time of the spool 2a exceeds the first threshold, and the distance deviated from the target position of the spool 2a is the second threshold In at least one of the cases where it is determined that the value has been exceeded, predetermined warning processing is performed. Although the specific content of the warning processing is arbitrary, for example, a management server (not shown) that manages the flow control valve 2, or the like, transmits a warning signal through a wireless or wired network, and displays it on display devices such as a management server You may display the warning content. Alternatively, the warning content may be displayed or audio output by a display device or a speaker connected to the flow control valve 2. An example of the warning content may be to urge the inspection of the spool 2a.

As described above, in the first embodiment, while the feedback control is in full swing so that the position of the spool 2a of the flow control valve 2 matches the target position, the unit time per unit time the spool 2a moves toward the target position Based on the number of times and at least one of the distance that the spool 2a is separated from the target position, the abrasion of the spool 2a when the spool 2a is in the neutral position to estimate the state of the spool 2a. Whether or not hydraulic oil is leaking can be determined simply and accurately.

(Second embodiment)

The second embodiment is to predict the life of the spool 2a of the flow control valve 2 based on the state estimated by the state estimation unit 5.

FIG. 3 is a diagram showing a schematic configuration of a fluid pressure drive device 10 having a valve body condition monitoring device 1 and a flow control valve 2 according to a second embodiment. The valve body condition monitoring device 1 in FIG. 3 has a life prediction unit 8 in addition to the configuration in FIG. 1. In addition, the acquisition unit 16 may be integrated with the feedback control unit 4 or the state estimation unit 5.

The life prediction unit 8 predicts the life of the spool 2a based on the state of the spool 2a of the flow control valve 2 estimated by the state estimation unit 5 over a predetermined period. Generally, since the spool 2a gradually wears out while in use, it is expected that the amount of hydraulic oil leaking out when the spool 2a is in the neutral position is also expected to increase gradually. However, when foreign matter contained in the hydraulic oil is mixed into the spool 2a, the leakage amount of the hydraulic oil may increase rapidly. As the leakage amount of the hydraulic oil increases, the number of times per unit time of the spool 2a and the distance separated from the target position increase.

When the number of times and the distance per unit time of the spool 2a, respectively, are to some extent, it is judged that the life of the spool 2a is determined, depending on the type and application of the flow control valve 2. Thus, the life prediction unit 8 may provide thresholds (third threshold and fourth threshold) that are determined to be the life of the spool 2a. For example, the life prediction unit 8 deviates from the target position of the spool 2a when the number of times per unit time of the spool 2a exceeds the third threshold (the third threshold is equal to or greater than the first threshold). In at least one case where the distance exceeded the fourth threshold (the fourth threshold is equal to or greater than the second threshold), the life of the spool 2a may be determined.

When the number of times the spool 2a exceeds the third threshold, or when the distance from the target position of the spool 2a exceeds the fourth threshold, a warning section 7 is provided to perform predetermined warning processing. May be

In addition, the life prediction unit 8 may determine that it is the life of the spool 2a at the point where a symptom of a sudden increase in the amount of leakage of hydraulic oil is seen. More specifically, with the passage of time, although the number and distance per unit time of the spool 2a tended to increase almost linearly, when the slope of the increase in the number and distance becomes greater at a certain point of time, , It may be judged that it is the life of the spool 2a at that point.

In this way, the criteria for determining that the life prediction unit 8 is the life of the spool 2a is considered various, but once it is determined that it is the life, it is preferable to notify the replacement time of the spool 2a by some means. Do. Various methods can be considered as the method of notification, and the above-mentioned warning unit 7 may perform.

In addition, the life prediction unit 8 may notify that the spool 2a has reached its end of life before reaching the end of life, or may also provide information on when the life ends at that time.

Thus, in the second embodiment, since the life prediction unit 8 for predicting the life of the spool 2a is provided based on the state estimated by the state estimation unit 5, the flow control valve 2 is During use, it is possible to prevent a problem in which a large amount of hydraulic oil leaks. In addition, since the replacement timing of the spool 2a can be grasped without disassembling the flow control valve 2 and inspecting the spool 2a itself, maintenance and repair costs of the flow control valve 2 can be reduced.

(Third embodiment)

The flow control valve 2 according to the third embodiment is used to drive an actuator such as a main valve or a cylinder.

FIG. 4 is a diagram showing a schematic configuration of a fluid pressure drive device 10 equipped with an actuator 9 in addition to the valve body condition monitoring device 1 and the flow rate control valve 2 in FIG. 3. The actuator 9 in FIG. 4 moves the movable part (second movable part) 9a up and down along the hydraulic fluid discharged from the flow control valve 2. Although the actuator 9 in FIG. 4 shows an example of controlling the fuel injection valve 11 and the exhaust valve 12 by compressed air by the movable portion 9a, the fuel injection valve 11 and the exhaust valve (12) is only an example. The specific structure and driving target of the actuator 9 in FIG. 4 are arbitrary.

The fluid pressure drive device 10 of FIG. 4 monitors the wear of the spool 2a of the flow control valve 2 in the state estimating unit 5 and the life predicting unit 8 while the actuator 9 is being driven. Can. More specifically, the number and distance per unit time of the spool 2a are measured at the timing of returning the spool 2a of the flow control valve 2 to the neutral position while the actuator 9 is being driven, and the state weight is added. The state of the spool 2a is estimated by the government 5. During the operation of the actuator 9, the spool 2a of the flow control valve 2 is returned to the neutral position periodically or irregularly, so each time, the number of spools 2a in the state estimating section 5 and By measuring the distance and estimating the state of the spool 2a, the state of the spool 2a can be continuously estimated while the actuator 9 is being driven.

Therefore, in the fluid pressure drive device 10 of Fig. 4, in order to estimate the state of the spool 2a of the flow control valve 2, it is not necessary to stop the fluid pressure drive device 10, and the actuator 9 While driving, it is possible to estimate the state of the spool 2a of the flow control valve 2.

As described above, in the third embodiment, in the fluid pressure drive device 10 that drives the actuator 9 with hydraulic oil discharged from the flow control valve 2, the flow control is performed while the actuator 9 is being driven in full swing. It is possible to determine whether the spool 2a is worn by the number and distance per unit time of the spool 2a, for example, in accordance with the timing at which the spool 2a of the valve 2 is returned to the neutral position. Thereby, since the presence or absence of abrasion of the spool 2a can be confirmed while driving the actuator 9, the presence or absence of abrasion of the spool 2a can be inspected without stopping the actuator 9.

(Fourth embodiment)

As a result of estimating the state of the spool 2a of the flow control valve 2 while driving the actuator 9, when the wear of the spool 2a is suspected, the driving of the actuator 9 is stopped once. You may change and estimate the state of the spool 2a of the flow control valve 2 based on the displacement speed of the movable part 9a of the actuator 9 in the state. In order to stop driving of the actuator 9, the spool 2a of the flow control valve 2 must be moved to a neutral position. As shown in Fig. 5, when the movable portion 9a of the actuator 9 is disposed in the vertical direction, when the spool 2a of the flow control valve 2 is moved to the neutral position, the movable portion 9a It will go down by self-respect. By the way, when the spool 2a of the flow control valve 2 is worn, even if the spool 2a is in the neutral position, since the hydraulic fluid flows from the flow control valve 2 toward the actuator 9, the movable part 9a ) Displacement speed is changed. Therefore, the change in the displacement speed of the movable portion 9a may be detected, and it may be determined again whether the spool 2a of the flow control valve 2 is worn.

FIG. 5 is a diagram showing a schematic configuration of a fluid pressure drive device 10 according to a modification of FIG. 4. The fluid pressure drive device 10 of FIG. 5 is disposed on one end of the movable part 9a, and the position detecting part 13 detects the position of the movable part 9a, and the movable part based on the positional change of the movable part 9a. It has a displacement detection unit 14 for detecting the displacement speed of 9a) and a state re-estimation 15 for estimating the state of the spool 2a of the flow control valve 2 again. The displacement detection unit 14 detects the displacement speed of the movable unit 9a by calculation based on the time change of the position of the movable unit 9a detected by the position detection unit 13.

The state re-estimation 15 in FIG. 5 is a state in which the operation of the actuator 9a is stopped while the actuator 9 is stopped, that is, the spool 2a of the flow control valve 2 is returned to the neutral position. Based on the displacement speed, the state of the spool 2a of the flow control valve 2 is again estimated. More specifically, if the displacement speed of the movable portion 9a becomes slower than a predetermined threshold, it is determined that the hydraulic oil leaks when the spool 2a of the flow control valve 2 is in the neutral position. As in the third embodiment, while the actuator 9 is being driven in full swing, when the wear of the spool 2a is estimated by the state estimating unit 5, the state is re-established while driving of the actuator 9 is stopped. When the abrasion of the spool 2a is estimated again by the government 15, the spool 2a may be finally determined to be worn.

In this way, in the fourth embodiment, when the wear of the spool 2a is estimated by the state estimating unit 5 while the actuator 9 is in full driving, the driving of the actuator 9 is stopped, and the state is re-established. The government 15 estimates again whether the spool 2a is worn. Thereby, it can be judged more accurately whether the spool 2a is stopped.

The actuator 9 in the fourth embodiment may be a flow control valve 9 different from the flow control valve 2. In this case, the other flow control valve 9 moves the spool (valve body) different from the spool 2a of the flow control valve 2. In the state estimating section 5, when the position of the spool 2a is shifted from the target position, the number of times per unit time the spool 2a is moved to return to the target position and the position of the spool 2a within a predetermined time The state of the spool 2a is estimated based on at least one of the distances away from the target position and the positions of the other spools of the other flow control valve 9.

In the above-described third and fourth embodiments, the fluid pressure drive device 10 including the flow control valve 2 and the actuator 9 has been described, but the configuration and operation of the actuator 9 are arbitrary. , It is widely applicable to the fluid pressure drive device 10 performing various operations using hydraulic oil discharged from the flow control valve 2. The flow control valve 2 has a spool 2a, and only needs to control the discharge amount of hydraulic oil according to the position of the spool 2a. The specific example of the flow control valve 2 is applicable also to a poppet valve, a ball valve, a needle valve, etc. besides the spool valve mentioned above. The actuator 9 has a movable portion 9a whose position is variable according to the discharge amount of hydraulic oil from the flow control valve 2, and in addition to directly driving the actuator shaft according to the position of the movable portion 9a, the movable portion 9a is Depending on the position, a valve may be used to control the amount of hydraulic oil supplied to the actuator 9 provided separately. A specific example of the drive portion may be a spool valve or a poppet valve, or a fluid pressure drive motor such as a hydraulic motor, in addition to the piston-type actuator 9 described above.

The technical spirit of the above-described embodiment can be summarized in the following (1) to (8).

(1) an acquisition unit for acquiring positional information of the valve body from a flow rate control valve that controls the discharge amount of the working fluid by performing feedback control to fix the valve body moving in the valve housing to a target position,

When the valve body is displaced from the target position, the valve body is based on at least one of the number of times per unit time the valve body is moved to return to the target position and the distance the valve body is deviated from the target position within a predetermined time. A valve body condition monitoring device comprising a state estimator for estimating the state of the vehicle.

(2) The valve body condition monitoring device according to (1), comprising a life prediction portion that predicts the life of the valve body based on the condition of the valve body estimated over a predetermined period by the condition estimating portion.

(3) a flow control valve having a valve body that moves within the valve housing and controlling the discharge amount of the working fluid,

A position detecting unit for detecting the position of the valve body in the valve housing,

A feedback control unit that performs feedback control to match the position of the valve body detected by the position detection unit to a target position;

When the position of the valve body is shifted from the target position, at least one of the number of times per unit time the valve body has been moved to return to the target position and the distance between the position of the valve body and the target body within a predetermined time. And a state estimator for estimating the state of the valve body based on the valve body.

(4) At least one of the case where the number of times per unit time the valve body is moved exceeds the first threshold and the distance between the valve body and the target position within a predetermined time exceeds the second threshold. The fluid pressure drive device according to (3), comprising a warning unit for performing predetermined warning processing.

(5) The fluid pressure drive device according to (3) or (4), comprising a life predicting unit for predicting the life of the valve body based on the state of the valve body estimated by the state estimating unit over a predetermined period of time.

(6) The fluid pressure driving device according to (5), wherein the state estimating unit estimates the state of the valve body when the valve body is stopped at a predetermined position.

(7) The fluid pressure driving device according to (6), wherein the state estimating unit estimates the state of the valve body when the valve body is moving.

(8) According to the discharge amount of the working fluid from the flow control valve, there is provided a different flow control valve for moving a valve body different from the valve body of the flow control valve,

The state estimating unit, when the position of the valve body is shifted from the target position, the number of times per unit time the valve body is moved to return to the target position and the position of the valve body are separated from the target position within a predetermined time. The fluid pressure drive device according to any one of (3) to (7), wherein the state of the valve body is estimated based on at least one of the distances and the position of the other valve body of the other flow control valve.

The aspect of the present invention is not limited to the above-described individual embodiments, but also includes various modifications that can be imagined by those skilled in the art, and the effects of the present invention are not limited to the above-mentioned contents. That is, various additions, modifications, and partial deletions are possible without departing from the conceptual spirit and spirit of the present invention derived from the contents defined in the claims and equivalents thereof.

1: Valve body condition monitoring device
2: Flow control valve
2a: spool
2b: valve rod
3: Position detection unit
4: Feedback control
5: state estimation unit
6: Memory
7: Warning
8: Life prediction unit
9: actuator
9a: moving part
10: fluid pressure drive device
11: fuel injection valve
12: exhaust valve
13: position detection unit
14: displacement detection unit
15: State re-estimation
20: controller

Claims (8)

An acquisition unit for acquiring positional information of the valve body from a flow rate control valve that controls the discharge amount of the working fluid by performing feedback control to fix the valve body moving in the valve housing to a target position;
When the valve body is displaced from the target position, the valve body is based on at least one of the number of times per unit time the valve body is moved to return to the target position and the distance the valve body is deviated from the target position within a predetermined time. And a state estimator for estimating the state of the valve body. The valve body condition monitoring apparatus according to claim 1, further comprising a life predicting unit for predicting the life of the valve body based on the state of the valve body estimated by the state estimating unit over a predetermined period of time. A flow control valve having a valve body moving in the valve housing and controlling the discharge amount of the working fluid,
A position detecting unit for detecting the position of the valve body in the valve housing,
A feedback control unit that performs feedback control to match the position of the valve body detected by the position detection unit to a target position;
When the position of the valve body is shifted from the target position, at least one of the number of times per unit time the valve body has been moved to return to the target position and the distance between the position of the valve body and the target body within a predetermined time. And a state estimator for estimating the state of the valve body based on the fluid pressure driving device. The method according to claim 3, wherein the number of times per unit time the valve body is moved exceeds a first threshold and a distance between the valve body and the target position within a predetermined time exceeds a second threshold. A fluid pressure drive device comprising a warning unit for performing predetermined warning processing on at least one side. The fluid pressure drive device according to claim 3 or 4, further comprising a life prediction unit for predicting the life of the valve body based on the state of the valve body estimated by the state estimation unit over a predetermined period of time. The fluid pressure driving device according to claim 5, wherein the state estimating unit estimates the state of the valve body when the valve body is stopped at a predetermined position. The fluid pressure drive device according to claim 6, wherein the state estimating unit estimates the state of the valve body when the valve body is moving. The valve body different from the valve body of the said flow control valve according to any one of Claims 3, 4, 6, and 7 according to the discharge amount of the working fluid from the said flow control valve. And other flow control valves,
The state estimating unit, when the position of the valve body is shifted from the target position, the number of times per unit time the valve body is moved to return to the target position and the position of the valve body are separated from the target position within a predetermined time. A fluid pressure drive device for estimating the state of the valve body based on at least one of the distances and the position of the other valve body of the other flow control valve.

Images